JP2009228266A - Removal method for buried structure under subaqueous ground plane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove a buried structure, which is buried under a subaqueous ground plane, by operations from above a water surface. <P>SOLUTION: A casing 2, which is large enough to internally take in the whole or a part of the buried structure (e.g. a sewer 1) to be removed, is driven; a casing driver, the leading end of which can penetrate the subaqueous ground plane, is mounted on a barge; and the barge is arranged on the water surface in the state of locating the casing driver in a position above the buried structure. The buried structure is wholly or partially taken in by making the leading end of the casing driver penetrate the subaqueous ground plane, while rotating the casing 2 by the casing driver; the subaqueous ground plane is excavated in the casing; the buried structure taken into the casing is pulled up from inside the casing and removed; and subsequently, the casing is pulled up. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a construction method for efficiently removing a buried structure buried under a water bottom ground surface by work from above the water surface.

As this type of removal method, Patent Document 1 proposes a method for removing a water bottom buried pipe. This is done by dripping the perimeter of the submerged buried pipe and removing the earth and sand around the buried pipe, cutting the buried pipe, and then lifting the cut buried pipe from the end with a wire. Then, the buried pipe is pulled up by a predetermined length by loosening the earth and sand in the upper part of the buried pipe one after another by jetting high-pressure jet water.
Japanese Patent Laid-Open No. 3-51592

However, since the conventional method requires diving work for cutting and lifting the submerged pipe, it is not always possible to perform efficient work including ensuring safety during diving work, and therefore the construction cost increases. It also takes a long construction period.
In addition, water pollution due to dredging is often unavoidable. For this reason, not only costs for pollution prevention measures are required, but it is also assumed that it takes a long time to discuss and adjust with fisheries cooperatives and related government agencies.
In addition, when the water bottom burial pipe to be removed is long, extensive dredging is necessary, and after removal, it is common to backfill with high quality soil. In general, large-scale dredging work and the accompanying residual soil disposal and backfilling usually require a great deal of labor and cost.

  The above-mentioned problem occurs not only when removing the water bottom buried pipe as shown in Patent Document 1, but also when removing various existing structures buried under the water bottom ground surface. However, the actual situation is that the development of an effective and appropriate construction method that can efficiently carry out this kind of removal work is desired.

  In view of the above circumstances, the present invention eliminates the need for diving work when removing the buried structure buried under the surface of the bottom of the water, and can prevent water pollution as much as possible. The purpose is to provide an effective and appropriate removal method that can greatly reduce

  The present invention is a method for removing an embedded structure buried under the surface of the bottom of the water by working from above the water surface, and is large enough to capture the entire buried structure to be removed or a part thereof. A casing driver capable of penetrating the bottom of the water bottom ground while driving the casing and mounting the casing driver on the pontoon, and positioning the casing driver at an upper position of the buried structure. By placing a trolley on the water surface and rotating the casing by the casing driver and penetrating the tip of the casing into the water bottom ground, the entire embedded structure or a part thereof is taken inside the tip of the casing, In this state, the bottom structure is excavated inside the casing and the buried structure taken into the casing is pulled up from the casing. After removal Te, characterized in that raising the casing.

  In the present invention, it is preferable that the bottom ground in the casing is excavated, the buried structure is pulled up and removed from the casing, the inside of the casing is backfilled, and then the casing is pulled up.

  In the present invention, it is possible to dismantle and remove the buried structure to be removed by the casing driver and the casing driven by the casing driver. In this case, the buried structure is cut at the tip of the casing. A possible cutting mechanism is attached, and the casing is penetrated into the underwater ground with the casing driver positioned above the dismantling work position, whereby a part of the embedded structure is cut and disassembled by the casing. At the same time, the dismantled material is taken into the casing, and then the water bottom ground in the casing is excavated to lift the dismantled material from the casing and remove it.

  In that case, after removing the dismantled object from the casing, the casing driver is moved by lifting the casing and moving the carrier, and the position at the position above the next dismantling work position It is preferable to dismantle and remove the entire buried structure by sequentially repeating the next dismantling work and the dismantling work for the buried structure.

According to the removal method of the present invention, the casing is driven by a casing driver mounted on a base boat and penetrated into the bottom of the ground, so that the buried structure to be removed is taken into the casing and then the buried structure from within the casing. Since all the work related to the removal can be carried out on the trolley, the diving work is unnecessary as in the past, and therefore the work efficiency is greatly improved, including the fact that it is easy to ensure work safety. Can do.
In addition, it is sufficient to excavate the water bottom ground only in the casing during removal, and in the case of backfilling, it is sufficient to back up only in the casing. This eliminates the need for dredging and the large-scale backfilling that accompanies it, which can achieve a significant improvement in work efficiency, thereby contributing to a sufficient reduction in construction cost and construction period. In addition, since the main work is only performed within the casing, there is little concern that the water area will be polluted over a wide range, and there is an advantage that the pollution control measures and adjustments of related government offices can be reduced.

Also, if the buried structure to be removed is long or large, it can be removed sequentially while cutting and disassembling the buried structure with the casing, so such a long or large buried structure. The removal work for the object can also be carried out efficiently.
In that case, the casing driver can be positioned easily and accurately by moving the carriage sequentially, and efficient removal work is also possible in this respect.

One embodiment of the removal method of the present invention will be described with reference to FIGS.
This embodiment is applied when removing the pipe rod 1 buried under the bottom of the water bottom, and as shown in FIG. 1, the bit 2a as a cutting mechanism is provided at the tip (lower end). The tip 2 of the casing 2 provided with is penetrated into the water bottom ground, so that the pipe rod 1 to be removed is cut by the casing 2 and disassembled, and at the same time the dismantled product is taken into the casing 2, and the dismantled product The main purpose is to pull up through the casing 2 and remove it.
In this embodiment, it is assumed that the pipe rod 1 to be removed has a concrete pipe with a thickness of about 100 mm on the outer surface of a steel pipe with an outer diameter of about 1 m (therefore, the overall outer diameter is about 1.2 mm). The inside diameter of the casing 2 for cutting, disassembling and removing it is assumed to be about 3 m. Therefore, in the present embodiment, the pipe rod 1 having an outer diameter of about 1.2 m is dismantled by being cut into pieces each having a length of about 3 m, and sequentially removed along the length direction.

  In the present embodiment, a known casing driver 3 is used as a mechanism for driving the casing 2 and penetrating into the water bottom ground to cut the pipe rod 1. Then, as shown in FIGS. 2 to 3, the casing driver 3 is mounted on a trolley 4 which is a general-purpose hydraulic engineering equipment, so that almost all the work related to the dismantling and removal of the pipe rod 1 is performed. Therefore, it is possible to eliminate the diving work as in the prior art.

The carriage 4 is equipped with the above-described casing driver 3, a crane 5 for performing various operations, and other related equipment, and is self-propelled or towed on the surface of the water. It is movable and can be placed in a fixed state at a fixed position.
In particular, the carriage 4 can be positioned with high accuracy with respect to a desired position. For this purpose, a position measuring mechanism such as a GPS mechanism and a mooring mechanism including winches 6 and anchors 7 installed at at least four corners are provided. After being provided and positioned by them, as shown in FIG. 2, the spud 8 can be fixed at that position by driving it into the water bottom ground. Accordingly, the carriage 4 can surely prevent the casing 2 from being inadvertently displaced during operation, and the driving reaction force by the casing driver 3 (the rotational reaction force and the press-fitting reaction force when the casing 2 is penetrated into the water bottom ground). ).

As the casing driver 3, for example, those disclosed in Japanese Patent Publication No. 58-19836 and Japanese Patent Publication No. 4-28078 can be suitably employed. These are press-fitted into the ground while rotating the large-diameter casing 2, and have been frequently used in the conventional excavation of boreholes.
The crane 5 includes various excavation devices such as hammer grabs and excavation buckets for excavating the inside of the casing 2 associated with the removal work of the pipe rod 1, and various types for grasping and lifting the dismantled material taken into the casing 2. Or a breaking device (not shown) such as a hammer for further breaking down the dismantled material in the casing 2 is operated.
In this embodiment, two casing drivers 3 and two cranes 5 are mounted, and the dismantling / removal operation for the pipe rod 1 can be performed simultaneously at two locations. It is not necessary to carry out this, and it is sufficient that at least one casing driver 3 is mounted on the carriage 4. Further, the crane 5 and other devices may be mounted on another trolley.

The basic work process of the removal method of the present embodiment is shown in FIG.
First, the carriage 4 is guided to the vicinity of the work position, and the casing driver 3 mounted on the carriage 4 is accurately positioned immediately above the position where the first dismantling and removal work is performed (upward position). The ship 4 is fixed.
Then, the casing driver 3 is driven and lowered while rotating the casing 2 as shown in (a), and the pipe rod 1 is cut and disassembled by the bit 2a at the tip, and penetrated into the underwater ground. . As shown in (b), when the tip of the casing 2 reaches below the buried position of the pipe rod 1, a short tubular body as a dismantled product separated from the pipe rod 1 is naturally taken into the casing 2.

Next, in this state, a drilling device such as a hammer grab or a drilling bucket is inserted into the casing 2, and the bottom ground is excavated inside the casing 2 as shown in FIG. Pull up and remove.
At that time, if possible, it is possible to hold the dismantled product as it is (with a short tube) and pull it up with an appropriate gripping device. It may be lifted after being dismantled to a size of 1 mm, or may be sufficiently divided and discharged together with excavated soil by a drilling device.

  The dismantled material is removed from the casing 2 as described above, and after the inside of the casing 2 is backfilled as shown in (d), if the casing 2 is pulled up, the removal process of one cycle is completed. 4 is moved to the next work position, and the casing 2 is positioned immediately above the next work position as shown in (e), and the same work is repeated there.

From then on, the above procedure is repeated in sequence to dismantle and remove the entire tube 1 to be removed along the length direction. As a basic replacement procedure, As shown in 5 (a) to (e), the casing 2 may be sequentially replaced at adjacent positions.
In this case, the carriage 4 may be moved by a distance corresponding to the radial dimension of the casing 2 along the length direction of the pipe rod 1, but the movement distance at the time of replacement as shown in the figure is reduced. By making it slightly smaller than the diameter dimension of the casing and slightly wrapping the next removal range with the previous removal range, it is possible to reliably prevent demolition from remaining between the two.

As described above, the removal method according to the present embodiment is configured by driving the casing 2 with the casing driver 3 to cut and dismantle the pipe rod 1 to be removed, and lift the dismantled object from the casing 2 to remove it. Therefore, it is possible to carry out all the work related to the removal of the pipe 1 from the carriage 4 and no diving work is required as in the prior art. Therefore, it is easy to ensure work safety. Work efficiency can be greatly improved.
In particular, according to the removal method of the present embodiment, it is sufficient to perform excavation and backfilling of the water bottom ground when removing the dismantled object with respect to the inside of the casing 2, and therefore, the total length of the pipe rod 1 as in the past. Therefore, it is not necessary to carry out large-scale dredging and backfilling, and in this respect, the work efficiency can be greatly improved, which can contribute to a sufficient reduction in work cost and work time.
Further, since the main work is only performed in the casing 2 in a limited manner, there is little concern that the water area will be polluted over a wide range, and there is an advantage that it is possible to reduce pollution prevention measures and adjustment with related government offices.

  Although one embodiment of the removal method of the present invention has been described above, the above embodiment is merely a preferred example, the present invention is not limited to the above embodiment, and does not depart from the gist of the present invention. If it is inside, various applications and design changes as exemplified below are possible for the entire process and procedure.

In the above embodiment, in order to remove the long pipe rod 1, as shown in FIG. 5, the casing 2 is sequentially replaced to the adjacent position. Positioning can be performed most easily and simply, except at the time of the first cutting shown in (a), with one end of the tube rod 1 being a free end as shown after (b) Since cutting is performed, an eccentric load is applied to the casing 2 at the time of cutting, and a case where smooth cutting cannot be performed is also assumed.
In order to avoid this, for example, as shown in FIG. 6, it is conceivable to cut and dismantle at intervals equivalent to one casing.
That is, after cutting and removing the first position as shown in FIG. 6 (a), the next removal position is a distance corresponding to two casings (here, one casing). The equivalent distance is a distance slightly smaller than the diameter of the casing because the lap cost is taken into consideration (the distance equivalent to two casings is twice the distance equivalent to one casing). After setting the position and cutting and removing the second time there, the third time, as shown in (c), back by a distance corresponding to one casing and remove the part left between them . Since the dismantle to be removed for the third time has already been cut off from other parts, the dismantle can be taken into the casing as it is without being cut.
Thereafter, by repeating the above states (b) to (c), that is, from the state (c), as shown in (d), it is moved by a distance corresponding to three casings and corresponds to two casings. After performing the removal work at a position with an interval of, it is possible to always perform stable and efficient cutting by moving backward by a distance corresponding to one casing as shown in (e). .

Alternatively, it is possible to further develop the procedure and simultaneously perform the cutting and removal steps for two places with two casings. That is, for example, as shown in FIG. 7 (a), in the first removal step, two casings are simultaneously cut and removed by two casings at an interval corresponding to one casing, and in the second removal step ( As shown in (b), the portion left by the previous step and the portion with a space corresponding to two casings are cut at the same time, and the subsequent steps are repeated as shown in (c). Removal work is possible.
In this case, as shown in FIG. 3, two casing drivers 3 are mounted on the carriage 4 and their distance (center-to-center distance) is initially equivalent to two casings. May be equivalent to three casings.

When excavating and backfilling the bottom ground in the casing 2 due to the removal of the pipe rod 1, in principle, the excavated soil should be disposed of as the remaining soil and then backfilled with good quality backfill soil. When it is unnecessary, that is, when the state where the excavation hole is left in the water bottom ground is allowed, the backfilling step may be omitted.
Further, when backfilling is performed, it is most preferable to pull up the casing 2 after backfilling the inside of the casing 2 as in the above embodiment. However, when the dismantled material is removed from the inside of the casing 2, the casing 2 is quickly removed. If it is lifted and it is allowed to be backfilled at a later stage, this may be done.

If excavated soil can be used as backfill soil, the current state will be restored automatically if the excavated soil is temporarily placed on, for example, a carrier for transporting earth and sand and reused as backfill soil. And there is no need to purchase backfill soil, so the cost can be reduced accordingly.
Furthermore, when backfilling with excavated soil as such, excavated soil generated by excavation in the casing 2 is temporarily placed without being temporarily placed in the casing excavated in the previous stage or in the subsequent stage. If it is thrown into the position where it was planned, the excavation work into the casing 2 and the backfill work using the excavated soil generated thereby can be carried out simultaneously.

In the above embodiment, the buried structure to be removed is the tube 1, so that the tube 1 is partially removed while being partially disassembled. For this purpose, the tube 1 is attached to the casing 2. It is assumed that the bit 2a that can be cut is provided, and the casing driver 3 is mounted on the carriage 4 and the entire pipe 1 is removed while being moved along the length of the pipe 1 in sequence. The present invention can be applied not only to removing such pipes 1 but also widely applicable to removing various existing buried structures buried under the water surface. What is necessary is just to set an optimal work procedure and the apparatus used for it optimally according to the form and magnitude | size of a removal target object.
For example, if the buried structure to be removed is relatively small, it is not necessary to cut or dismantle the buried structure by using the casing 2 having a size that can be taken in as it is (therefore, in the casing) No cutting mechanism is required), and the whole can be simply removed as it is. Of course, if the buried structure to be removed is large in plan, the removal work may be performed on the entire buried structure while moving the carriage 4 not only in one direction but also in two horizontal directions.
In addition, if the casing driver 3 is mounted so as to be movable with respect to the carriage 4, the carriage 4 remains fixed at a fixed position without moving the carriage 4 each time the casing 2 is replaced. It can be changed by moving the casing driver 3 on the ship 4.

The embodiment of the removal construction method of the present invention is shown, and is a diagram showing an outline when the buried structure to be removed is a pipe rod. It is a side view which shows the trolley equipped with the casing driver. It is a top view of the same carrier. It is a figure which shows a basic work procedure same as the above. It is a figure which shows the basic replacement procedure same as the above. It is a figure which shows the other example of the replacement procedure same as the above. It is a figure which shows the further another example of the replacement procedure same as the above.

Explanation of symbols

1 pipe (buried structure to be removed)
2 Casing 2a Bit (cutting mechanism)
3 Casing driver 4 Cargo ship 5 Crane 6 Winch 7 Anchor 8 Spud

Claims (4)

A construction method for removing an embedded structure buried under the water surface by working from above the water surface,
A casing driver capable of driving the casing having a size capable of taking in the whole or a part of the buried structure to be removed inside and rotating the casing while allowing the tip of the casing to penetrate into the submarine ground. With the casing driver positioned on the upper position of the buried structure, and placing the trolley on the water surface,
By rotating the casing by the casing driver and penetrating the tip of the casing into the water bottom ground, the entire embedded structure or a part thereof is taken into the inside of the tip of the casing,
In this state, the subsurface ground excavated inside the casing and the buried structure taken in the casing is lifted and removed from the casing, and then the casing is pulled up. Removal method. A method for removing a buried structure under a water bottom ground according to claim 1,
An excavation of the submarine ground in the casing, the buried structure is lifted and removed from the casing, the interior of the casing is backfilled, and then the casing is lifted up. Removal method. A method for removing a buried structure under a water bottom ground according to claim 1 or 2,
A cutting mechanism capable of cutting the buried structure is attached to the tip of the casing in order to remove the buried structure to be removed by the casing driver and the casing driven by the casing driver while disassembling,
With the casing driver positioned at a position above the dismantling operation position, the casing is penetrated into the underwater ground so that a part of the embedded structure is cut and disassembled by the casing and the dismantled material is taken into the casing. ,
After that, a method for removing the buried structure under the surface of the water bottom ground, wherein the water bottom ground in the casing is excavated and the dismantled material is lifted and removed from the inside of the casing. A method for removing the buried structure under the water bottom ground according to claim 3,
A part of the buried structure is disassembled by the casing and the dismantled material taken into the casing is removed from the casing, and then the casing driver is moved up by lifting the casing to disassemble the casing driver. It is characterized by dismantling and removing the entire buried structure by sequentially repeating the work of positioning above the work position, the next dismantling work on the buried structure at that position, and the dismantling work removal work. The removal method of the buried structure under the water bottom ground.

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